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| author | Ian Kent <raven@themaw.net> | 2022-10-18 10:32:42 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-10-20 13:54:26 +0200 |
| commit | aa1d058d48f292aa138e33ad12b7b4d18b5407cd (patch) | |
| tree | b217058e2baa1422788a68bf13a628d41110bde3 /fs/kernfs | |
| parent | 5033ac5c580cb22245a0c2b9e53d508e8fdd50d8 (diff) | |
| download | linux-aa1d058d48f292aa138e33ad12b7b4d18b5407cd.tar.gz linux-aa1d058d48f292aa138e33ad12b7b4d18b5407cd.tar.bz2 linux-aa1d058d48f292aa138e33ad12b7b4d18b5407cd.zip | |
kernfs: dont take i_lock on inode attr read
The kernfs write lock is held when the kernfs node inode attributes
are updated. Therefore, when either kernfs_iop_getattr() or
kernfs_iop_permission() are called the kernfs node inode attributes
won't change.
Consequently concurrent kernfs_refresh_inode() calls always copy the
same values from the kernfs node.
So there's no need to take the inode i_lock to get consistent values
for generic_fillattr() and generic_permission(), the kernfs read lock
is sufficient.
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Ian Kent <raven@themaw.net>
Link: https://lore.kernel.org/r/166606036215.13363.1288735296954908554.stgit@donald.themaw.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/kernfs')
| -rw-r--r-- | fs/kernfs/inode.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c index 3d783d80f5da..74f3453f4639 100644 --- a/fs/kernfs/inode.c +++ b/fs/kernfs/inode.c @@ -190,10 +190,8 @@ int kernfs_iop_getattr(struct user_namespace *mnt_userns, struct kernfs_root *root = kernfs_root(kn); down_read(&root->kernfs_rwsem); - spin_lock(&inode->i_lock); kernfs_refresh_inode(kn, inode); generic_fillattr(&init_user_ns, inode, stat); - spin_unlock(&inode->i_lock); up_read(&root->kernfs_rwsem); return 0; @@ -288,10 +286,8 @@ int kernfs_iop_permission(struct user_namespace *mnt_userns, root = kernfs_root(kn); down_read(&root->kernfs_rwsem); - spin_lock(&inode->i_lock); kernfs_refresh_inode(kn, inode); ret = generic_permission(&init_user_ns, inode, mask); - spin_unlock(&inode->i_lock); up_read(&root->kernfs_rwsem); return ret; |